Laser-Induced Positional and Chemical Lattice Reordering Generating Ferromagnetism

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Theo Pflug - , Mittweida University of Applied Sciences (Author)
  • Javier Pablo-Navarro - , University of Zaragoza (Author)
  • Md Shabad Anwar - , Chair of Applied Solid State Physics, Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Markus Olbrich - , Mittweida University of Applied Sciences (Author)
  • César Magén - , University of Zaragoza (Author)
  • Manuel Ricardo Ibarra - , University of Zaragoza (Author)
  • Kay Potzger - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Jürgen Faßbender - , Chair of Applied Solid State Physics, Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Jürgen Lindner - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Alexander Horn - , Mittweida University of Applied Sciences (Author)
  • Rantej Bali - , Helmholtz-Zentrum Dresden-Rossendorf (Author)

Abstract

Atomic scale reordering of lattices can induce local modulations of functional material properties, such as reflectance and ferromagnetism. Pulsed femtosecond laser irradiation enables lattice reordering in the picosecond range. However, the dependence of the phase transitions on the initial lattice order as well as the temporal dynamics of these transitions remain to be understood. This study investigates the laser-induced atomic reordering and the concomitant onset of ferromagnetism in thin Fe-based alloy films with vastly differing initial atomic orders. The optical response to single femtosecond laser pulses on selected prototype systems, one that initially possesses positional disorder, Fe60V40, and a second system initially in a chemically ordered state, Fe60Al40, has been tracked with time. Despite the vastly different initial atomic orders the structure in both systems converges to a positionally ordered but chemically disordered state, accompanied by the onset of ferromagnetism. Time-resolved measurements of the transient reflectance combined with simulations of the electron and phonon temperatures reveal that the reordering processes occur via the formation of a transient molten state with an approximate lifetime of 200 ps. These findings provide insights into the fundamental processes involved in laser-induced atomic reordering, paving the way for controlling material properties in the picosecond range.

Details

Original languageEnglish
Article number2311951
JournalAdvanced functional materials
Volume34
Issue number13
Publication statusPublished - 25 Mar 2024
Peer-reviewedYes

Keywords

Keywords

  • atomic reordering, chemical order, ferrmagnetism, positional order, pump-probe reflectometry